This application represents the first competitive renewal for our Training in Bacteriology T32 program that currently supports 3 predoctoral and 1 Ph.D. postdoctoral trainees per year. Our program, which is based at the University of Pennsylvania and Children's Hospital of Philadelphia, includes 10 laboratories directed by well established principle investigators located on a single contiguous campus. This program has allowed us to recruit some of the best and brightest trainees from among a talented pool at Penn where students and post-docs have a very large number of microbiology labs to choose among. The organized training mission of this program has helped our efforts to collaborate and interact more effectively as a group: unlike our first application, our trainers now have several joint NIH grants, a growing number of joint publications, and a network of collaborations that involve our trainees. Compared to four years ago, our program has five new trainers with more likely to be added in the near future as several new assistant professors establish their research programs. Our research in progress meetings and seminars within the microbiology program have helped spur the rapid growth of exciting, collaborative work in bacterial pathogenesis, microbial immunopathogenesis, and bacterial metagenomics, with institutional support for deep-sequencing facilities, bioinformatics, and a germ-free mouse core playing important roles in these efforts. Because of our increasing emphasis on genomic approaches and technologies, we have updated the title of our program to Training in Microbial Pathogenesis and Genomics to more accurately reflect its breadth by including microbial genomic studies. This rapidly evolving area has been the focus of the projects chosen by three of our best recent predoctoral trainees as well as one of our predoctoral graduates who is now a postdoctoral fellow with Jeff Gordon at Washington University. In light of this, we have modified our training program to accommodate trainees who are interested in microbial genomics, adding new mentors, courses, and training activities. To date, a total of 12 trainees from 7 different laboratories have been supported by this T32, including 5 Ph.D. students, 4 M.D./Ph.D. students and 3 Ph.D. postdoctoral fellows. Of our trainees, 7/12 are been women and 3/12 are under-represented minorities. The research opportunities provided by the trainers coupled with strong institutional commitment and an extensive and well-organized training program will continue to provide excellent training in microbial pathogenesis and genomics to both students and postdoctoral fellows.